LXR linux/drivers/s390/cio/idset.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *    Copyright IBM Corp. 2007, 2012
   4 *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   5 */
   6
   7#include <linux/vmalloc.h>
   8#include <linux/bitmap.h>
   9#include <linux/bitops.h>
  10#include "idset.h"
  11#include "css.h"
  12
  13struct idset {
  14        int num_ssid;
  15        int num_id;
  16        unsigned long bitmap[0];
  17};
  18
  19static inline unsigned long bitmap_size(int num_ssid, int num_id)
  20{
  21        return BITS_TO_LONGS(num_ssid * num_id) * sizeof(unsigned long);
  22}
  23
  24static struct idset *idset_new(int num_ssid, int num_id)
  25{
  26        struct idset *set;
  27
  28        set = vmalloc(sizeof(struct idset) + bitmap_size(num_ssid, num_id));
  29        if (set) {
  30                set->num_ssid = num_ssid;
  31                set->num_id = num_id;
  32                memset(set->bitmap, 0, bitmap_size(num_ssid, num_id));
  33        }
  34        return set;
  35}
  36
  37void idset_free(struct idset *set)
  38{
  39        vfree(set);
  40}
  41
  42void idset_fill(struct idset *set)
  43{
  44        memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id));
  45}
  46
  47static inline void idset_add(struct idset *set, int ssid, int id)
  48{
  49        set_bit(ssid * set->num_id + id, set->bitmap);
  50}
  51
  52static inline void idset_del(struct idset *set, int ssid, int id)
  53{
  54        clear_bit(ssid * set->num_id + id, set->bitmap);
  55}
  56
  57static inline int idset_contains(struct idset *set, int ssid, int id)
  58{
  59        return test_bit(ssid * set->num_id + id, set->bitmap);
  60}
  61
  62static inline int idset_get_first(struct idset *set, int *ssid, int *id)
  63{
  64        int bitnum;
  65
  66        bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
  67        if (bitnum >= set->num_ssid * set->num_id)
  68                return 0;
  69        *ssid = bitnum / set->num_id;
  70        *id = bitnum % set->num_id;
  71        return 1;
  72}
  73
  74struct idset *idset_sch_new(void)
  75{
  76        return idset_new(max_ssid + 1, __MAX_SUBCHANNEL + 1);
  77}
  78
  79void idset_sch_add(struct idset *set, struct subchannel_id schid)
  80{
  81        idset_add(set, schid.ssid, schid.sch_no);
  82}
  83
  84void idset_sch_del(struct idset *set, struct subchannel_id schid)
  85{
  86        idset_del(set, schid.ssid, schid.sch_no);
  87}
  88
  89/* Clear ids starting from @schid up to end of subchannel set. */
  90void idset_sch_del_subseq(struct idset *set, struct subchannel_id schid)
  91{
  92        int pos = schid.ssid * set->num_id + schid.sch_no;
  93
  94        bitmap_clear(set->bitmap, pos, set->num_id - schid.sch_no);
  95}
  96
  97int idset_sch_contains(struct idset *set, struct subchannel_id schid)
  98{
  99        return idset_contains(set, schid.ssid, schid.sch_no);
 100}
 101
 102int idset_is_empty(struct idset *set)
 103{
 104        return bitmap_empty(set->bitmap, set->num_ssid * set->num_id);
 105}
 106
 107void idset_add_set(struct idset *to, struct idset *from)
 108{
 109        int len = min(to->num_ssid * to->num_id, from->num_ssid * from->num_id);
 110
 111        bitmap_or(to->bitmap, to->bitmap, from->bitmap, len);
 112}
 113